Structural and optical investigation of Cd4Se96−xSx (x = 4, 8, 12) chalcogenide thin films

Abstract

Cd 4 Se 96-x S x with x = 4, 8, 12 chalcogenide semiconductor has been prepared by melt-quenching technique. Thin films were deposited by thermal evaporation technique on ultra clean glass substrates under a high vacuum of 10 -6 Torr and were characterized by XRD, SEM, FTIR and Raman spectroscopy. XRD confirms the prepared films are in nanoscale region having polycrystalline nature with preferred orientation along (002) plan. Optical properties (optical band gap, absorption coefficient, extinction coefficient, refractive index) were investigated in the frequency range of 190-1100 nm. Analysis of the optical measurement shows that the non-direct transition is dominant. It is observed that the optical band gap increase with sulfur (S) concentration. The Dark conductivity as a function of temperature in the temperature range 300-390 K was investigated, which shows that it is thermally activated process. The conductivity increases on the incorporation of Sulfur content, which may be due to shift in Fermi level.

Cd(Zn, S)Se quaternary thin films for electrochemical photovoltaic cell application

“…Such an impurity addition increases the energy gap because of shifting in Fermi level. S replaces Se atoms in the CdSe host causing an increase in disorder in the energy gap . Similarly, Zn reduces the Se ring structure and increases the disorderliness of Cd‐Se‐Zn material .…”

“…Optical studies establish a simple way of obtaining energy bandgap (E g ) and to analyse the effects of defect states in the band structure. 31 The optical absorption coefficient (α) is calculated to determine the PV behaviour of the materials. Figure 4A shows that the absorption coefficient for all the samples is high and is in the range of 10 4 to 10 5 cm −1 .…”

“…S replaces Se atoms in the CdSe host causing an increase in disorder in the energy gap. 31 Similarly, Zn reduces the Se ring structure and increases the disorderliness of Cd-Se-Zn material. 32 Thus, the integration of the doped Zn and S elements with CdSe enables the increased energy gap of Cd 1−x Zn x S y Se 1−y material.…”

Structural, Morphology and Some Optical Properties of Chalcogenide Ga<sub>80-x</sub>Se<sub>x</sub>Te<sub>20</sub> (Where x = 10%, 15% and 20%) Glassy Material

“…This is most likely due to their high optical transparency in the IR region, strong optical nonlinearity, high photo sensitivity, ease of fabrication and processing, and good chemical durability. Chalcogenide glasses based on the chalcogen elements S, Se, Te are used widely in ultra-fast optical switches, frequency converters, optical amplifiers, optical recording devices, an optical integrated circuit for IR operations and infrared transmitting optical fibers [4]- [10]. Ga-X systems where elements X = S, Se or Te have revealed to be particular interest [10].…”

“…Chalcogenide glasses based on the chalcogen elements S, Se, Te are used widely in ultra-fast optical switches, frequency converters, optical amplifiers, optical recording devices, an optical integrated circuit for IR operations and infrared transmitting optical fibers [4]- [10]. Ga-X systems where elements X = S, Se or Te have revealed to be particular interest [10]. In the present article, the structural, morphological and some optical properties of Ga 80−x Se x Te 20 (where X = 10%, 15% and 20%) have been studied with thickness ranging between 165 nm, 615 nm and 1027 nm.…”